There are mysteries beyond our understanding, and feeding cherry shrimp can seem like one of those—especially when you first start out.

Cherry shrimp often seem to eat invisible food, or rather food we cannot see. Their diet doesn’t seem consistent: they consume veggies and algae wafers, and also dine delicately on departed relatives … they are as happy gobbling down a food pellet as they are shoveling up microscopic gunk. They can spend days banqueting on a carrot. All this makes the process of feeding shrimp seem rather vague.

Let’s try to clear it up.

I. The Basics: An overview of feeding aquarium shrimp

II. How Cherry Shrimp Eat: The biology and natural feeding behavior of neocaridina shrimp (This article!)

III. The Edible Aquarium: Promoting biofilm in your shrimp tank

IV. Feeding Cherry Shrimp: Primary foods and special treats (Coming soon)

In part one of this series, we went over the basics of cherry shrimp feeding. In this post we’ll go deeper, looking at the shrimp’s anatomy and feeding mechanics for clues to their care. We’ll also look at how cherry shrimp eat in the wild. Fair warning, it gets a little weird…

Basic Cherry Shrimp Anatomy

To begin with, no shrimp-keeper worth the name will have failed to realize our gentle pets are bristling with artillery. Okay, the only real weaponry they have is armor, and that only works for predators in their size category … but the complexity of their bio high-tech is intense and fascinating.

■ Cherry shrimp have 3 pairs of differently sized antenna: a pair of long sweepers, and two shorter pairs of special antennae called antennules for balance, orientation, and “taste.” There hasn’t been much detailed study on cherry shrimp antennae, but we can extrapolate from crustaceans that have attracted more research. Shrimp find their food mainly by dissolved “smells” detected by these antenna.

■ Multiple pairs of little-bitty swimmeretes line the underside of the shrimp’s long abdomen. These odd appendages wave merrily about to empower shrimp to levitate, hover and maneuver for our entertainment.

■ Three pairs of jointed ‘walking’ legs move and grip independently—maybe four if you count the front pair used for feeding. Straddling pebbles, clinging upside down, sticking to the glass: it’s all the same to them.

How these tiny beasts keep track of all those moving pieces is just part of the shrimp mystery.

Focus: Feeding Legs

On top of all that bioware is a completely DIFFERENT set of tools: the shrimp’s feeding arms (or legs, or whatever). Cherry shrimp have 2 pairs of little grabber arm/legs, plus the bigger fore claw (which may be a pair of front legs modified for eating). Each limb of this feeding apparatus hinges to make a quick back-and-forth conveyor system, moving potential food up to the little open beak-port we’ll call the shrimp’s mouth.

The feeding legs operate in an orchestrated motion, whirling any food they can scrape up to their mouth. The leg claws don’t seem to actually place food into its mouth, but rather to fling it in the right direction and hope some lands.

Perhaps their beak-mouths sort out the yummy good goo from the unsavory … but how? Can cherries see the swirling mass of microscopic life it preys preys upon? What makes one patch better than another, and how do they know? Science is silent on the details.

Truth is Stranger than Fiction

All this seems to be as sensible as feeding yourself by flinging thimble-fulls of food at your mouth from six inches away. But even if the shrimp’s system of eating seems whack, they clearly prosper well enough to help feed the world with this silliness.

 We can suspect that inefficiency serves a larger purpose. The shrimp’s churning method of feeding cleans away debris, biofilm, and other gunk besides just the food. The ‘wasted’ particles drift away in the water, available to tinier creatures and bacteria we don’t see. The scouring for food also has a healthy effect on plants by reducing algae and bacterial rot.

Shrimp get into tiny crevices others cannot reach; they are a unique underwater cleaning crew. It’s good for the environment when shrimp take a long time to finish a meal!

Cherry Shrimp in the Wild

As any owner of cherry shrimp has probably notices, shrimp keep up their whirligig feeding motion almost constantly, pausing only occasionally for silent meditation. It is far from clear that shrimp ever actually do get ‘full.’ Since their stomachs are tiny, said to be the size of their eyeball, their grazing is nonstop by necessity.

Go check your shrimp, they are doing it right now!

The streams and quietly flowing waters of the cherry shrimp’s natural environment is teeming with life. With millions of creatures and detritus layered over the environment, just about anywhere the wild cherry lands is packed with edibles. The neocaridina shrimp’s instinctive feeding behavior is omnivorous and opportunistic.

So, cherry shrimp aren’t picky eaters, but they are adapted to variety. No one foodstuff can replace all the nutrients in a healthy cherry shrimp’s natural diet.

TIP: One way to see if your colony is getting enough food is to check their digestive tract. This thin line runs along the shrimp’s “spine” from its head to its tail. It’s easier to spot in individuals with less color. The line should be dark  and unbroken (ie, full of food).

Feeding Conclusions

New aquariums can be a tough environment for cherry shrimp. It takes time for an aquariums to grow a strong ecosystem that supports adequate grazing—new tanks are quite sterile. Helping our tanks grow biofilm and a burgeouning infustroial population helps cherries feed more naturally, and makes the whole process of feeding healthier and easier.

Shrimps play an important role in keeping a balanced environment, consuming both decaying matter and microbial lifeforms. Observing how cherry shrimp eat in the wild, we can understand why shrimp graze constantly on different surfaces. We also see why frequent small portions are better than a big meal, and why a variety of food is necessary.

In the Next post, we’ll discuss how to season our tanks into booming shrimp pastures.